Angle measuring instrument

ABSTRACT

An angle-measuring instrument comprises a sighting device which is supported in two brackets for tilting about a first axis and which, together with said brackets, is rotatable about a second axis. Two double levers in close adjacency to one another are so mounted on one of said brackets that each said lever can be turned, over a mid-position, into two extreme positions. The midpositions of said two levers are substantially parallel to one another. Said levers, in their one extreme positions, cause gears to impede rotation of the sighting device about the axes and, in their other extreme positions, release the sighting device for rotation. The close adjacency of said levers to one another facilitates their operation.

United States Patent 1191 Feist et al.

ANGLE-MEASURING INSTRUMENT [75] inventors: Wieland Feist; Peter Navratil; Roman Seifert, all of Jena, Germany [73] Assignee: Jenoptik Jena G.m.b.H., Jena, Gera,

Germany [22] Filed: April 30, 1971 [21] Appl. No.: 141,053

[52] U.S.Cl. ..248/183 [51] 1nt.CI. ..B23q 1/04 [58] Field otSearch ..248/183;74/479,520,544

[56] References Cited UNITED STATES PATENTS 1,825,577 9/1931 Carr ..74/479 2,318,910 5/1943 Zucker ..248/l83 2,459,040 1/1949 ..248/183 3,446,502 5/1969 Damron et a1 ..74/479 FOREIGN PATENTS OR APPLICATIONS 807,720 7 1951 Germanym; ..24s 1s3 111 3,713,612 1 1 Jan. 30, 1973 905,429 3/1954 Germany ..74/520 97,178 2/1961 Netherlands ..74/479 360,216 3/1962 Switzerland ..248/183 Primary Examiner-Marion Parsons, Jr.

[57] ABSTRACT An angle-measuring instrument comprises a sighting device which is supported in two brackets for tilting about a first axis and which, together with said brackets, is rotatable about a second axis. Two double levers in close adjacency to one another are so mounted on one of said brackets that each said lever can be turned, over a mid-position, into two extreme positions. The mid-positions of said two levers are substantially parallel to one another. Said levers, in their one extreme positions, cause gears to impede rotation of the sighting device about the axes and, in their other extreme positions, release the sighting device for rotation. The close adjacency of said levers to one another facilitates their operation.

1 Claim, 5 Drawing Figures I PATENTEDJAN 30 1975 INVENTOR S Mama I14 ANGLE-MEASURING INSTRUMENT This invention relates to angle-measuring instruments of the kind comprising a sighting device rotatable about two axes, for example to theodolites.

As is well known, theodolites and similar instruments which are fitted with a telescope that rotates about two axes at right angles to one another, and are used for measuring angles in two orthogonal planes, have clamping means for arresting the telescope in any desired position. The clamping means comprise a hand switch and a transmission system which connects the switch either to the telescope direct orto a graduated disc, a lever or a diaphragm thereof. The construction and arrangement and, in particular, the manipulation of the clamping means are of considerable importance to the measurement as regards both time and accuracy. Following the trend towards automation and rationalization in the construction and use of angle-measuring instruments, two hand switches in the form of levers or knobs are so placed in close adjacency to one another on one side of the instrument housing as to be accessible to the operator with a minimum of arm and hand motion. Since the operator is compelled to manipulate the two levers or knobs the very moment he has brought the target approximately center into the telescope field of vision, and he may not take his eye off the eyepiece, he has to feel for them and, in doing so, may easily mistake the one for the other. However, even a mere shifting of the hand from one lever or knob to the other is waste of time.

The present invention aims at rationalizing and facilitating the manipulation of angle-measuring instruments for sighting distant targets by providing the instrument with clamping means which are fitted with two switches so constructed and arranged that the operators hand need not change from one switch to the other, so that mistakes and unnecessary groping are avoided to a considerable extent.

To this end the present invention consists in providing an angle-measuring instrument of the kind comprising a sighting device rotatable about two axes and two closely spaced hand switches each of which can be turned over a mid-position to two extreme positions for respectively preventing and permitting rotation of the sighting device about the axis to which the respective switch is allotted, wherein the switches are in the form of two-armed levers the mid-positions of which are substantially parallel to one another. Thus it is possible for the operator to set both levers single-handed, the thumb contacting the one lever and the index finger the other, so that two clamping means can be operated simultaneously and the time for sighting a target for the measurement of the horizontal and vertical angles is shortened.

Preferably, two corresponding ends of the twoarmed-levers are close to one another in each extreme position. This arrangement, in which thumb and index press against two unidirected lever ends, provides an additional and very effective safeguard against interference with the setting of the sighting device. It is furthermore advantageous that the two two-armed levers be co-axial with one another.

In order that the invention may be more readily understood, reference is made to the accompanying drawings, which illustrate diagrammatically and by way of example three embodiments thereof, and wherein FIG. 1 is a view of one embodiment,

FIG. 2 shows another embodiment,

FIG. 3 is a view of a third embodiment, together with clamping means,

FIG. 4 is a view of the third embodiment, at right angles to the view illustrated in FIG. 3, and

FIG. 5 is a section on the line A A of FIG. 4.

In FIG. 1 of the drawings, a limbus 2 attaching a pivot 1 carries an alidade 3 which is rotatable about an axis L,L,. The alidade 3 is provided with a vertical circle (not shown) and carries a telescope 5 which pivots in supports 4 (only one support shown) about an axis K,I(,. Thus, the telescope 5 can rotate in two orthogonal planes respectively containing the axes L L and K,K,, the plane of L,L, being parallel to that of the drawing. The support 4 not shown carries a housing 6 for the vertical circle, and the support 4 shown is provided with two two-armed levers which extend parallel to the plane of the drawing and can be turned, away from parallel mid-positions M,-M,, to extreme positions 7, 7' and 8, 8', respectively. The levers 7 and 8 in their one extreme positions, cause connecting means (not shown) respectively to clamp the alidade 3 and the telescope 4, thus preventing rotation about the axes L L and K K and when assuming their other extreme positions 7' and 8' (shown in broken lines), cause the connecting means respectively to release the alhidade 3 and the telescope 4, thus permitting rotation about the said axes.

In FIG. 2, two two-armed levers extending parallel to the plane of the drawing can be turned away from parallel mid-positions M M to extreme positions 9, 9' and 10, 10, respectively. While the levers 7 and 8 in FIG. 1 are parallel to one another only when in midposition, the levers 9 and 10 of FIG. 2 are parallel also in their extreme positions, namely the clamping and releasing positions.

In FIG. 3 to 5, a tubular part 11 rigidly connected to the telescope (not shown) is rotatable about an axis K K,. The part 11 and the telescope are also rotatable relatively to a carrier 12 (shown only in part) about an axis L L at right angles to K K A spindle 14 is mounted in a bearing 16. The one end of the spindle 14 carries a clamping means 15 which is in close adjacency to a face 13 of the part 11. The other end of the spindle 14 is connected to a switch by three interlinked levers l7, 18, 19. Both the lever 19 and the switch 20 are rigidly connected to a journal 22 mounted in a part 21 of the housing (not shown).

In the part 21 there is also mounted a journal 23 the two ends of which are respectively fixed to a switch 24 and a lever 25. A spindle 27 is mounted in a bearing 26. The one end of the spindle 27 carries a clamping means 28 which is in close adjacency to the carrier 12. The other efid of the spindle 27 is attached to a lever 29. The free ends of the levers and 29 are linked together by a lever 30. The switches 20, 24 are in the form of double levers and have a stop 31 located therebetween.

The arrangement of the switches 20, 24 differs from that of the switches in the device of FIG. 1 and 2 in that their mid-positions are substantially at right angles to the axis L, L,.

In the positions illustrated in FIG. 3 and 4, the switches 20, 24 contact the stop 31, and the clamping means 15 and 28 are respectively raised from the part 11 and the carrier 12, so that the telescope can freely rotate about the axes K K and L, L The end 20a of the switch 20 and the end 24a of the switch 24 are closer to one another than are the other ends 20b and 24b. Pressure on the ends 20b, 24b causes them to approach one another and widens the gap between the ends 200 and 24a. Rotation of the switch 20 is transmitted through the journal 22, the levers 19, 18, 17 to the spindle 14, which rotates in its bearing 16 and urges the clamping means against the part 1 1, thus inhibiting rotation of the telescope about the axis X, K Analogously thereto, rotation of the switch 24 is transmitted through the journal 23, the levers 25, 30, 29 to the spindle 27, which rotates in its bearing 26 and urges the clamping means 28 against the carrier 12, thus inhibiting rotation of the telescope about the axis L L The part 11 and the limbus 12 also function as stops which prevent the ends b and 24b approaching one another more closely than can the ends 202, 24a in the opposite case. The distance of the clamping means 15 from the part 11, the pitch of the spindle l4 and the rotation of the lever 19 respectively correspond to the distance of the clamping means 28 from the limbus 12, the pitch of the spindle 27, and the rotation of the lever 29.

The matter in the above description or shown in the accompanying drawings are to be interpreted as illustrative and not in a limiting sense. It is also possible, for example, to attach the levers 20 and 24 to a common axis, one above the other.

We claim:

1. An angle-measuring instrument for measuring angles in two orthogonal planes, comprising a carrier an alidade said alidade being mounted on said carrier for rotation about an axis in a first plane, two brackets secured to said alidade a telescope mounted between said brackets for rotation about an axis in a second plane, said two axes being mutually at right angles, two clamping means for respectively controlling the rotations of said telescope in said two planes, two switches for respectively operating said two clamping means, switches being rotatably mounted in close adjacency to one another on one of said brackets, and two lever systems fitted in said one bracket for kinematic connection of said switches to said clamping means, each one of said lever systems being located between one of said clamping means and one of said switches, said switches being pivotable between two extreme positions through mid-positions that are substantially at right angles to one another, each of said switches in its one extreme position arresting rotation and it its other extreme position releasing rotation. 

1. An angle-measuring instrument for measuring angles in two orthogonal planes, comprising a carrier an alidade said alidade being mounted on said carrier for rotation about an axis in a first plane, two brackets secured to said alidade a telescope mounted between said brackets for rotation about an axis in a second plane, said two axes being mutually at right angles, two clamping means for respectively controlling the rotations of said telescope in said two planes, two switches for respectively operating said two clamping means, switches being rotatably mounted in close adjacency to one another on one of said brackets, and two lever systems fitted in said one bracket for kinematic connection of said switches to said clamping means, each one of said lever systems being located between one of said clamping means and one of said switches, said switches being pivotable between two extreme positions through mid-positions that are substantially at right angles to one another, each of said switches in its one extreme position arresting rotation and it its other extreme position releasing rotation. 